CN104360143B - Current zero-crossing point detects circuit and method, load voltage detection circuit and method - Google Patents
Current zero-crossing point detects circuit and method, load voltage detection circuit and method Download PDFInfo
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- CN104360143B CN104360143B CN201410729856.2A CN201410729856A CN104360143B CN 104360143 B CN104360143 B CN 104360143B CN 201410729856 A CN201410729856 A CN 201410729856A CN 104360143 B CN104360143 B CN 104360143B
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
- H03K5/153—Arrangements in which a pulse is delivered at the instant when a predetermined characteristic of an input signal is present or at a fixed time interval after this instant
- H03K5/1536—Zero-crossing detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/13—Modifications for switching at zero crossing
- H03K17/133—Modifications for switching at zero crossing in field-effect transistor switches
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/60—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors
- H03K17/68—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors specially adapted for switching ac currents or voltages
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
- H03K5/22—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral
- H03K5/24—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral the characteristic being amplitude
- H03K5/2436—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral the characteristic being amplitude using a combination of bipolar and field-effect transistors
- H03K5/2454—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral the characteristic being amplitude using a combination of bipolar and field-effect transistors using clock signals
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
- H03K5/22—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral
- H03K5/24—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral the characteristic being amplitude
- H03K5/2463—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral the characteristic being amplitude using diodes
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/382—Switched mode power supply [SMPS] with galvanic isolation between input and output
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0084—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only
Abstract
A kind of current zero-crossing point detection circuit and method, load voltage detection circuit and method, the current zero-crossing point detect circuit, including：Load power source circuit, divider resistance, switching tube, zero-crossing detection circuit, the load power source circuit includes load, diode and inductance, second end of divider resistance described in switching tube is grounded together with the second end of the switching tube, it is controlled using the switching tube for load voltage, the partial pressure end of the divider resistance is connected with the signal input part of zero-crossing detection circuit, using zero-crossing detection circuit judge diode current whether zero crossing, so as to obtain the diode current flow time.And the load voltage detection circuit utilizes diode current flow time and switching tube ON time, can obtain load voltage.The circuit structure is simple, and detection efficiency is high, and cost is low.
Description
Technical field
The present invention relates to electric circuit inspection technical field, more particularly to a kind of current zero-crossing point detection circuit and corresponding electric current
Zero-crossing examination method, load voltage detection circuit and corresponding load voltage detection method.
Background technology
With LED fast development, the design of LED drive circuit emerges in an endless stream.But existing LED drive circuit is defeated
The design for going out the function aspects such as overload, overvoltage protection is all more complicated.Common LED load detection circuit using transformer around
Group, causes circuit integrally more complicated, and volume is big, and cost is high.
The content of the invention
The problem of present invention is solved is to provide a kind of current zero-crossing point detection circuit and method, load voltage detection circuit and
Method, can quickly obtain load voltage and can quickly judge diode current zero crossing, circuit small volume, cost is low.
To solve the above problems, circuit is detected the embodiments of the invention provide a kind of current zero-crossing point, including：Load power source
Circuit, divider resistance, switching tube, zero-crossing detection circuit, the load power source circuit include load, diode and inductance, and
The load, diode and inductance connect to form loop circuit, one end and the operating voltage input of the load power source circuit
It is connected, the other end of the load power source circuit is connected with the first end of switching tube, the first end of divider resistance, described point
Second end of piezoresistance is grounded together with the second end of the switching tube, is controlled using the switching tube for load voltage,
The partial pressure end of the divider resistance is connected with the signal input part of zero-crossing detection circuit, is judged using zero-crossing detection circuit
Diode current whether zero crossing.
Optionally, the zero-crossing detection circuit includes signal input part, sampling and keep module, the second reference voltage module
With the second comparator, the sampling and keep module is connected with the second reference voltage module, and one end of the sampling and keep module
It is connected with signal input part, one end of the second reference voltage module is used as the first input end of the second comparator, the letter
Number input as the second comparator the second input.
Optionally, one end for being loaded in the load power source circuit, the negative pole of diode are connected with operating voltage input
Connect, the other end of the load is connected with one end of inductance, the other end of the inductance be connected with the positive pole of diode and
The first end of first end, divider resistance with switching tube is connected.
Optionally, the load power source circuit includes：Transformer Winding, diode and load, described load one end and two
The negative pole of pole pipe is connected, and the load other end is connected with one end of Transformer Winding secondary, the Transformer Winding pair
The other end on side is connected with the positive pole of diode, and one end of the Transformer Winding primary side is connected with operating voltage input
Connect, the other end of the Transformer Winding primary side is connected with the first end of switching tube, the first end of divider resistance.
Optionally, one end, the one end of inductance loaded in the load power source circuit is connected with operating voltage input,
The other end of the load is connected with negative pole one end of diode, positive pole one end of the diode and the other end phase of inductance
Connect and the first end with switching tube, the first end of divider resistance are connected.
Optionally, the load is LED.
Optionally, the load is parallel with the second electric capacity.
The embodiment of the present invention additionally provides a kind of current zero-crossing point detection using described current zero-crossing point detection circuit
Method, including：
The voltage waveform at the partial pressure end of divider resistance is gathered using divider resistance；
When switching tube closing, diode current flow, sampling keeps the partial pressure terminal voltage of divider resistance, and the voltage is subtracted into base
The partial pressure terminal voltage of divider resistance of the result of quasi- voltage with obtaining in real time is compared, when the partial pressure terminal voltage obtained in real time
When instantaneous voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing.
Optionally, the reference voltage is the voltage of the second reference voltage module.
The embodiment of the present invention additionally provides a kind of load voltage detection circuit, including：Load power source circuit, divider resistance,
Switching tube, voltage detecting circuit and zero-crossing detection circuit, the load power source circuit include load, diode and inductance, and
The load, diode and inductance connect to form loop circuit, one end and the operating voltage input of the load power source circuit
It is connected, the other end of the load power source circuit is connected with the first end of switching tube, the first end of divider resistance, described point
Second end of piezoresistance is grounded together with the second end of the switching tube, is controlled using the switching tube for load voltage,
The partial pressure end of the divider resistance is connected with the signal input part of voltage detecting circuit, the signal input part of zero-crossing detection circuit
Connect, diode current zero crossing is judged using zero-crossing detection circuit, obtain diode current flow time, the voltage detecting circuit
Sampled using partial pressure end the voltage kept, and switching tube ON time and diode current flow time, obtain load voltage.
Optionally, the voltage detecting circuit includes the first signal input part, secondary signal input, sampling holding mould
Block, voltage selection module and averaging module, first signal input part are connected with one end of sampling and keep module, to partial pressure
The voltage at end carries out sampling holding, and the other end of the sampling and keep module is connected with the first end of voltage selection module, described
The second end ground connection of voltage selection module, the secondary signal input is connected with voltage selection module, for input diode
ON time and switching tube ON time, the selection end of the voltage selection module are connected with one end of averaging module, average mould
Block is averaged during switching tube is turned on diode current flow to the signal inputted, and its average value exported is load electricity
Pressure.
Optionally, the zero-crossing detection circuit includes signal input part, sampling and keep module, the second reference voltage module
With the second comparator, the sampling and keep module is connected with the second reference voltage module, and one end of the sampling and keep module
It is connected with signal input part, one end of the second reference voltage module is used as the first input end of the second comparator, the letter
Number input as the second comparator the second input.
Optionally, the load voltage detection circuit and zero-crossing detection circuit share sampling and keep module.
Optionally, the voltage detecting circuit, zero-crossing detection circuit are located in load control circuit, when detecting load
Electric voltage over press, the control end on-off switching tube of load control circuit controlling switch pipe.
Optionally, the first end of the switching tube is connected with the other end of load power source circuit, and the of the switching tube
Two ends are grounded, and the control end of the switching tube is connected with load control circuit.
Optionally, one end for being loaded in the load power source circuit, the negative pole of diode are connected with operating voltage input
Connect, the other end of the load is connected with one end of inductance, the other end of the inductance be connected with the positive pole of diode and
The first end of first end, divider resistance with switching tube is connected.
Optionally, the load power source circuit includes：Transformer Winding, diode and load, one end of the load with
The negative pole of diode is connected, and the other end of the load is connected with one end of Transformer Winding secondary, the transformer around
The other end of group secondary is connected with the positive pole of diode, one end and the operating voltage input phase of the Transformer Winding primary side
Connection, the other end of the Transformer Winding primary side is connected with the first end of switching tube, the first end of divider resistance.
Optionally, one end, the one end of inductance loaded in the load power source circuit is connected with operating voltage input,
The other end of the load is connected with negative pole one end of diode, positive pole one end of the diode and the other end phase of inductance
Connect and the first end with switching tube, the first end of divider resistance are connected.
Optionally, the load is LED.
Optionally, the load is parallel with the second electric capacity.
The embodiment of the present invention additionally provides a kind of load voltage detection method that circuit is detected using described load voltage,
Including：
The voltage at divider resistance partial pressure end is gathered using divider resistance；
When switching tube closing, diode current flow, sampling keeps the voltage at divider resistance partial pressure end, and the voltage is subtracted into base
The partial pressure terminal voltage of divider resistance of the result of quasi- voltage with obtaining in real time is compared, when the partial pressure terminal voltage obtained in real time
When instantaneous voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing, so as to obtain
Obtain the diode current flow time；
Obtain after the diode current flow time, the voltage at the partial pressure end kept using sampling, and switching tube ON time and two
Pole pipe ON time, calculates and obtains load voltage.
Optionally, in switching tube ON time, the partial pressure end for holding of being sampled during the previous cycle diode current flow of sampling
Voltage, in the diode current flow time, the sampled voltage in two periods is averaged, its average value is just by 0V voltages of sampling
It is load voltage.
Compared with prior art, the technical program has advantages below：
Technical solution of the present invention is carried out after partial pressure by divider resistance, can be readily detected by zero-crossing detection circuit
Diode current zero crossing, obtains the ON time of diode, and detection efficiency is high, and cost is low.
The technical program detects diode current zero crossing first with zero-crossing detection circuit simultaneously, obtains diode current flow
Time, load voltage detection circuit is recycled, the voltage at the partial pressure end kept of sampling, and switching tube ON time and two is utilized
Pole pipe ON time, calculates and obtains load voltage, and simple in construction, detection efficiency is high, and cost is low.
Brief description of the drawings
Fig. 1 is that the load voltage of first embodiment of the invention detects the structural representation of circuit；
Fig. 2 is the structural representation of the zero-crossing detection circuit of the embodiment of the present invention；
Fig. 3 is the structural representation of the voltage detecting circuit of the embodiment of the present invention；
Fig. 4 and Fig. 5 are the voltage and current waveforms of the embodiment of the present invention；
Fig. 6 is that the load voltage of second embodiment of the invention detects the structural representation of circuit；
Fig. 7 is that the load voltage of third embodiment of the invention detects the structural representation of circuit.
Embodiment
Below in conjunction with the accompanying drawings, by specific embodiment, clear, complete description is carried out to technical scheme.
Fig. 1 is refer to, is a kind of load voltage detection circuit of the embodiment of the present invention, including：Load power source circuit 14, point
Piezoresistance 16, switching tube 15, voltage detecting circuit 18 and zero-crossing detection circuit 19, the load power source circuit 14 include load
11st, diode 13 and inductance 12, and the load 11, diode 13 and the series connection of inductance 12 form loop circuit, the load electricity
One end of source circuit 14 is connected with operating voltage input Vin, the other end and the switching tube 15 of the load power source circuit 14
First end, the first end of divider resistance 16 be connected, the second end of the divider resistance 16 is together with the of the switching tube 15
Two ends are grounded, and are controlled using the switching tube 15 for load voltage, and partial pressure end and the voltage of the divider resistance 16 are examined
Signal input part, the signal input part of zero-crossing detection circuit 19 of slowdown monitoring circuit 18 are connected, and utilize zero-crossing detection circuit 19
Judge diode current whether zero crossing, obtain the diode current flow time, the voltage detecting circuit 18 obtained by holding of sampling
The partial pressure end feedback voltage of divider resistance 16 is obtained, and utilizes switching tube ON time and diode current flow time, is obtained by computing
Take load voltage.
In the present embodiment, the load power source circuit 14 includes diode 13, inductance 12 and load 11, the load 11
One end, the negative pole of diode 13 be connected with operating voltage input Vin, the one of the other end and the inductance 12 of the load 11
End is connected, and the other end of the inductance 12 is connected with the positive pole of diode 13 and the first end with switching tube 15, partial pressure electricity
The first end of resistance 16 is connected.
In the present embodiment, the load 11 is LED.And the diode 13 is consistent with LED direction.
In other embodiments, the load can also be other electricity devices, using the voltage detecting circuit to negative
The voltage of load is detected.
Be also associated with the first electric capacity C1 between the operating voltage input Vin and earth terminal, first electric capacity be for
Maintain the stabilization of operating voltage.In other embodiments, the LED two ends are also associated with the second electric capacity, second electric capacity
For being filtered to load current.
The first end of the switching tube 15 is connected with the other end of load power source circuit 14, and the second of the switching tube 15
End ground connection, the control end of the switching tube 15 is connected with load control circuit 17.
In the present embodiment, the switching tube is MOS transistor.In other embodiments, the switching tube can also be
Triode etc..
In the present embodiment, the divider resistance 16 includes the first divider resistance R1 and the second divider resistance R2, utilizes institute
State the first divider resistance R1 and the second divider resistance R2 and the voltage of the first end of switching tube 15 is subjected to partial pressure, the first divider resistance R1
And the of the signal input part of the second partial pressure end between divider resistance R2 and zero-crossing detection circuit 19, voltage detecting circuit 18
One signal input part is connected.
In other embodiments, the divider resistance can also be resistance, and the partial pressure end of divider resistance and zero passage
Signal input part, the first signal input part of voltage detecting circuit of point detection circuit are connected.
In the present embodiment, Fig. 2 is refer to, the zero-crossing detection circuit 19 includes signal input part 91, sampling and kept
Module 93, the second reference voltage module 94 and the second comparator 95, the reference voltage module of sampling and keep module 93 and second
94 are connected, and one end of the sampling and keep module 93 is connected with signal input part 91, the second reference voltage module 94
One end as the second comparator 95 first input end, the signal input part 91 as the second comparator 95 second input
End.
After switching tube shut-off, during diode current flow, the sampling and keep module 93 is obtained to signal input part 91
Partial pressure end feedback voltage VFBSampling holding is carried out, sampling is obtained and keeps voltage VFBS, and pass through the electricity of the second reference voltage module 94
Press V1 so that the voltage of the first input end of the second comparator 95 is VFBS-V1.Fed back by the second comparator 95 and partial pressure end
Voltage VFBReal-time voltage be compared.Work as VFBInstantaneous voltage is less than VFBSDuring-V1, the second comparator 95 is overturn, you can judged
For diode current zero crossing.
Diode current zero crossing can be readily available using the zero-crossing detection circuit 19, so as to obtain diode
ON time.The zero-crossing detection circuit 19 can be formed individually with load power source circuit 14, divider resistance 16, switching tube 15
One current zero-crossing point detects circuit, for detecting diode current zero crossing.And in the present embodiment, the zero-crossing examination
Circuit 19 was obtained after the diode current flow time, using to diode current flow time and switching tube ON time, load voltage detection
Circuit 18 can be readily available load voltage.
In the present embodiment, Fig. 3 is refer to, the voltage detecting circuit 18 is believed including the first signal input part 81, second
Number input 82, sampling and keep module 83, voltage selection module 84 and averaging module 85, first signal input part 81 is with adopting
Sample keeps one end of module 83 to be connected, and carries out sampling holding to the voltage at the partial pressure end of divider resistance, the sampling keeps mould
The other end of block 83 is connected with the first end of voltage selection module 84, the second end ground connection of the voltage selection module 84, is
0V, the secondary signal input 82 is connected with voltage selection module 84, is led for input diode ON time and switching tube
Logical time, the selection end of the voltage selection module 84 is connected with one end of averaging module 85, and averaging module 85 is led in switching tube
The signal inputted is averaged during logical and diode current flow, in switching tube ON time, the voltage selection module 84
Selection end be connected with the first end of the voltage selection module 84, the voltage at partial pressure end that keeps of sampling is averaged,
Diode current flow time, the selection end of the voltage selection module 84 is connected with the second end of the voltage selection module 84, will
0V voltages are averaged, and its average value exported is exactly load voltage.
When circuit works in continuous current mode or critical continuous mode current-mode, the continuous current mode refers to two
During pole pipe afterflow, inductive current, which declines, not yet reaches zero, that is, carries out next switch periods, inductive current is always remained as just
Value, during the critical continuous mode current-mode refers to diode continuousing flow, when inductive current drops to zero, is carried out next immediately
Switch periods, inductive current has a point to be zero in each cycle, partial pressure end feedback voltage VFBWaveform as shown in figure 4, its
Middle K=R2/ (R1+R2).When switching tube is opened, VFB=0；When switching tube is turned off, and inductive current be on the occasion of when, diode
Conducting, ignores the conduction voltage drop of diode, VFB=K*Vin.The time scale of switching tube conducting is D, the time of diode current flow
Ratio is D '=(1-D).
When circuit works in discontinuous current mode, during the discontinuous current mode refers to diode continuousing flow, inductance electricity
Stream has descended to zero, and after a period of time, just carries out next switch periods, and inductive current has one section in each cycle
Time is zero, partial pressure end feedback voltage VFBWaveform it is as shown in Figure 5：Switching tube shut-off, and inductive current be on the occasion of when, two poles
Pipe is turned on, and ignores the conduction voltage drop of diode, VFB=K*Vin；During diode current flow, inductive current is gradually reduced, and works as electricity
When inducing current drops to 0, diode is automatically shut down, and the voltage of switching tube first end is begun to decline, partial pressure end feedback voltage VFBWith
The voltage of switching tube first end is proportional to be declined.When detecting partial pressure end feedback voltage VFBVoltage during less than diode current flow,
Inductive current zero crossing can be judged as.
In the present embodiment, the sampling keeps the voltage of 83 pairs of previous cycle diode current flow time-division pressure sides to adopt
Sample is kept, in switching tube ON time, the selection end of the voltage selection module 84 and the first of the voltage selection module 84
End is connected, and the voltage at the partial pressure end kept of sampling is averaged, in the diode current flow time, the voltage selection module 84
Selection end is connected with the second end of the voltage selection module 84,0V voltages is averaged, equivalent to the partial pressure end according to Fig. 5
Feedback voltage VFBReconstruct a VFBSDotted line waveform (see Fig. 5), when switching tube 15 is opened, dotted line waveform voltage is previous
Partial pressure end feedback voltage V during cycle diode current flowFB, i.e. K*Vin.At other moment, dotted line waveform voltage ground is 0.
To dotted line waveform in D and D ' between carry out that average (D is the time scale that switching tube is turned on, and D ' is the time ratio of diode current flow
Example), you can obtain LED voltage K*VLED=K*Vin*D/ (D+D ').For continuous current mode or critical current pattern, D '=
(1-D)；For discontinuous current mode D '<The time that (1-D), switching tube and diode are not turned on, averaging module is without flat
.
In the present embodiment, zero-crossing detection circuit 19, voltage detecting circuit 18 are located at same load control circuit 17
Or in control chip, when the load control circuit 17 or control chip are used to obtain diode current flow time and switching tube conducting
Between, while when detecting load voltage overvoltage, utilizing the control end Vc closing switchs pipe 15 of switching tube.
The voltage detecting circuit 18 and zero-crossing detection circuit 19 share same sampling and keep module or using different
Sampling and keep module.
In the present embodiment, the control end of the zero-crossing detection circuit 19, voltage detecting circuit 18 and switching tube 15
It can be located in different control chip or load control circuit.
Second embodiment of the invention additionally provides another load voltage detection circuit, refer to Fig. 6, remainder all phases
Together, only load power source circuit is differed, and the load power source circuit 20 includes：Transformer Winding 22, the electricity of diode 23, second
Hold 24 and load 21, one end is connected with the negative pole of diode 23 after 21 parallel connections of second electric capacity 24 and load, described second
The other end is connected with one end of the secondary of Transformer Winding 22 after 21 parallel connections of electric capacity 24 and load, the secondary of Transformer Winding 22
The other end be connected with the positive pole of diode 23, one end of the primary side of Transformer Winding 22 and operating voltage input Vin
It is connected, the other end of the primary side of Transformer Winding 22 is connected with the first end of switching tube 15, the first end of divider resistance 16
Connect.
Because the time that switching tube 15 is turned on is D, the ON time of diode 22 is D ', and both sides relation meets D*Vin=D ' *
N*Vo, Vo are exactly output voltage, i.e. LED voltage, and n is the no-load voltage ratio of transformer 22；The waveform of switching tube first end is reconstructed in the D periods
The voltage (Vin+n*Vo) of switching tube first end during for diode current flow, D ' periods voltage is 0；By this voltage in (the D+D ') time
It is interior averagely to be obtained D* (Vin+n*Vo)/(D+D ')=n*Vo, i.e. output loading voltage.
In other embodiments, the both sides of the load can not also be parallel with the second electric capacity.
Third embodiment of the invention additionally provides another load voltage detection circuit, refer to Fig. 7, remainder all phases
Together, only load power source circuit is differed, and the load power source circuit 30 includes：Diode 33, inductance 32, the and of the second electric capacity 34
One end, one end of inductance 32 and the operating voltage input Vin phases of load 31, the load 31 and the parallel-connection structure of the second electric capacity 34
Connection, the load 31 and the other end of the parallel-connection structure of the second electric capacity 34 are connected with negative pole one end of diode 33, and described two
Positive pole one end of pole pipe 33 is connected with the other end of inductance 32 and the first end with switching tube 15, the first end of divider resistance 16
It is connected.
Because the time that switching tube 15 is turned on is D, the ON time of diode 22 is D ', and both sides relation meets D*Vin=D ' *
Vo, reconstructs the voltage (Vin+Vo) of waveform switching tube first end when the D periods are diode current flow of the first end of switching tube 15, D '
Period voltage is 0；This voltage is averagely obtained into D* (Vin+Vo)/(D+D ')=Vo within (the D+D ') time, that is, exports negative
Carry voltage.
In other embodiments, the both sides of the load can not also be parallel with the second electric capacity.
Based on foregoing circuit, the embodiment of the present invention provide firstly a kind of current over-zero point detecting method, including：
The voltage waveform at the partial pressure end of divider resistance is gathered using divider resistance；
When switching tube is closed, during diode current flow, sampling keeps the partial pressure terminal voltage of divider resistance, and the voltage is subtracted into base
The partial pressure terminal voltage of divider resistance of the result of quasi- voltage with obtaining in real time is compared, when the partial pressure terminal voltage obtained in real time
When instantaneous voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing.
In addition, detecting circuit based on above-mentioned load voltage, the embodiment of the present invention additionally provides a kind of load voltage detection side
Method, including：
The voltage at divider resistance partial pressure end is gathered using divider resistance；
When switching tube is closed, during diode current flow, sampling keeps the voltage at divider resistance partial pressure end, and the voltage is subtracted into base
The partial pressure terminal voltage of divider resistance of the result of quasi- voltage with obtaining in real time is compared, when the partial pressure terminal voltage obtained in real time
When instantaneous voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing, so as to obtain
Obtain the diode current flow time；
Obtain after the diode current flow time, the voltage at the partial pressure end kept using sampling, and switching tube ON time and two
Pole pipe ON time, calculates and obtains load voltage.
In the first embodiment of the invention, when switching tube 15 is opened, the dotted line waveform voltage that sampling is kept is previous
Partial pressure end feedback voltage V during cycle diode current flowFB, i.e. K*Vin., will using voltage selection module in diode current flow
Output voltage is grounded, and output voltage is adjusted to 0V, to dotted line waveform in D and D ' between carry out that average (D is the time that switching tube is turned on
Ratio, D ' is the time scale of diode current flow), you can obtain LED voltage K*VLED=K*Vin*D/ (D+D ').
In second embodiment of the invention, because the time that switching tube 15 is turned on is D, the ON time of diode 22 is D ',
Both sides relation meets D*Vin=D ' * n*Vo, reconstructs the waveform of the switching tube first end switching tube when the D periods are diode current flow
The voltage (Vin+n*Vo) of first end, D ' periods voltage is 0；This voltage is averagely obtained into D* (Vin within (the D+D ') time
+ n*Vo)/(D+D ')=n*Vo, i.e. output loading voltage.
In third embodiment of the invention, because the time that switching tube 15 is turned on is D, the ON time of diode 22 is D ',
Both sides relation meets D*Vin=D ' * Vo, reconstructs the waveform of the switching tube first end switching tube the when the D periods are diode current flow
The voltage (Vin+Vo) of one end, D ' periods voltage is 0；This voltage is averagely obtained into D* (Vin+ within (the D+D ') time
Vo)/(D+D ')=Vo, i.e. output loading voltage.
Although the present invention is disclosed as above with preferred embodiment, it is not for limiting the present invention, any this area
Technical staff without departing from the spirit and scope of the present invention, may be by the methods and techniques content of the disclosure above to this hair
Bright technical scheme makes possible variation and modification, therefore, every content without departing from technical solution of the present invention, according to the present invention
Any simple modifications, equivalents, and modifications made to above example of technical spirit, belong to technical solution of the present invention
Protection domain.
Claims (20)
1. a kind of current zero-crossing point detects circuit, it is characterised in that including：Load power source circuit, divider resistance, switching tube, mistake
Zero-detection circuit, the load power source circuit includes load, diode and inductance, and the load, diode and inductance string
Connection forms loop circuit, and one end of the load power source circuit is connected with operating voltage input, the load power source circuit
The other end be connected with the first end of switching tube, the first end of divider resistance, the second end of the divider resistance is together with described
Switching tube the second end ground connection, be controlled using the switching tube for load voltage, the partial pressure end of the divider resistance with
The signal input part of zero-crossing detection circuit is connected, and the current zero-crossing point of diode is obtained using zero-crossing detection circuit, its
In, the zero-crossing detection circuit includes signal input part, sampling and keep module, the second reference voltage module and second and compared
Device, the sampling and keep module is connected with the second reference voltage module, and one end of the sampling and keep module is inputted with signal
End is connected, and one end of the second reference voltage module is used as the first input end of the second comparator, the signal input part work
For the second input of the second comparator.
2. current zero-crossing point as claimed in claim 1 detects circuit, it is characterised in that loaded in the load power source circuit
One end, the negative pole of diode are connected with operating voltage input, and the other end of the load is connected with one end of inductance, institute
State that the other end of inductance is connected with the positive pole of diode and the first end with switching tube, the first end of divider resistance are connected.
3. current zero-crossing point as claimed in claim 1 detects circuit, it is characterised in that the load power source circuit includes：Become
Depressor winding, diode and load, one end of the load are connected with the negative pole of diode, the other end of the load and change
One end of depressor winding secondary is connected, and the other end of the Transformer Winding secondary is connected with the positive pole of diode, described
One end of Transformer Winding primary side is connected with operating voltage input, the other end and switching tube of the Transformer Winding primary side
First end, the first end of divider resistance is connected.
4. current zero-crossing point as claimed in claim 1 detects circuit, it is characterised in that loaded in the load power source circuit
One end, one end of inductance are connected with operating voltage input, and the other end of the load is connected with negative pole one end of diode
Connect, positive pole one end of the diode is connected with the other end of inductance and the first end with switching tube, the first of divider resistance
End is connected.
5. current zero-crossing point as claimed in claim 1 detects circuit, it is characterised in that the load is LED.
6. current zero-crossing point as claimed in claim 1 detects circuit, it is characterised in that the load is parallel with the second electric capacity.
7. the current zero-crossing point described in a kind of utilization claim 1~6 any one detects the current zero-crossing point detection side of circuit
Method, it is characterised in that including：
The voltage waveform at the partial pressure end of divider resistance is gathered using divider resistance；
When switching tube closing, diode current flow, sampling keeps the partial pressure terminal voltage of divider resistance, and the voltage is subtracted into benchmark electricity
The partial pressure terminal voltage of divider resistance of the result of pressure with obtaining in real time is compared, instantaneous when the partial pressure terminal voltage obtained in real time
When voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing.
8. current over-zero point detecting method as claimed in claim 7, it is characterised in that the reference voltage is the second benchmark electricity
The voltage of die block.
9. a kind of load voltage detects circuit, it is characterised in that including：Load power source circuit, divider resistance, switching tube, voltage
Circuit and zero-crossing detection circuit are detected, the load power source circuit includes load, load, diode and inductance, and described negative
Carry, diode and inductance connect to form loop circuit, one end of the load power source circuit is connected with operating voltage input,
The other end of the load power source circuit is connected with the first end of switching tube, the first end of divider resistance, the divider resistance
The second end together with the switching tube the second end be grounded, be controlled using the switching tube for load voltage, described point
The partial pressure end of piezoresistance is connected with the signal input part of voltage detecting circuit, the signal input part of zero-crossing detection circuit, profit
With zero-crossing detection circuit judge diode current whether zero crossing, obtain the diode current flow time；The voltage detecting circuit
Sampled using partial pressure end the voltage kept, and switching tube ON time and diode current flow time, obtain load voltage, wherein,
The zero-crossing detection circuit includes signal input part, sampling and keep module, the second reference voltage module and the second comparator, institute
Sampling and keep module is stated with the second reference voltage module to be connected, and one end and the signal input part phase of the sampling and keep module
Even, one end of the second reference voltage module is as the first input end of the second comparator, and the signal input part is used as the
Second input of two comparators.
10. load voltage as claimed in claim 9 detects circuit, it is characterised in that the voltage detecting circuit includes first
Signal input part, secondary signal input, sampling and keep module, voltage selection module and averaging module, first signal are defeated
Enter end with one end of sampling and keep module to be connected, sampling holding is carried out to the voltage at partial pressure end, the sampling and keep module
The other end is connected with the first end of voltage selection module, and the second end ground connection of the voltage selection module, the secondary signal is defeated
Enter end with voltage selection module to be connected, for input diode ON time and switching tube ON time, the voltage selects mould
The selection end of block is connected with one end of averaging module, averaging module switching tube turn on and diode current flow during to being inputted
Signal is averaged, and its average value exported is load voltage.
11. load voltage as claimed in claim 9 detects circuit, it is characterised in that the load voltage detection circuit and mistake
Zero-detection circuit shares sampling and keep module.
12. load voltage as claimed in claim 9 detects circuit, it is characterised in that the voltage detecting circuit, zero crossing inspection
Slowdown monitoring circuit be located at load control circuit in, when detect load voltage overvoltage, the control end of load control circuit controlling switch pipe
On-off switching tube.
13. load voltage as claimed in claim 9 detects circuit, it is characterised in that the first end of the switching tube and load
The other end of power circuit is connected, the second end ground connection of the switching tube, control end and the load control electricity of the switching tube
Road is connected.
14. load voltage as claimed in claim 9 detects circuit, it is characterised in that loaded in the load power source circuit
One end, the negative pole of diode are connected with operating voltage input, and the other end of the load is connected with one end of inductance, institute
State that the other end of inductance is connected with the positive pole of diode and the first end with switching tube, the first end of divider resistance are connected.
15. load voltage as claimed in claim 9 detects circuit, it is characterised in that the load power source circuit includes：Transformation
Device winding, diode and load, one end of the load are connected with the negative pole of diode, the other end and transformation of the load
One end of device winding secondary is connected, and the other end of the Transformer Winding secondary is connected with the positive pole of diode, described to become
One end of depressor winding primary side is connected with operating voltage input, the other end of the Transformer Winding primary side and switching tube
First end, the first end of divider resistance are connected.
16. load voltage as claimed in claim 9 detects circuit, it is characterised in that loaded in the load power source circuit
One end, one end of inductance are connected with operating voltage input, and the other end of the load is connected with negative pole one end of diode
Connect, positive pole one end of the diode is connected with the other end of inductance and the first end with switching tube, the first of divider resistance
End is connected.
17. load voltage as claimed in claim 9 detects circuit, it is characterised in that the load is LED.
18. load voltage as claimed in claim 9 detects circuit, it is characterised in that the load is parallel with the second electric capacity.
19. the load voltage described in a kind of utilization claim 9~18 any one detects the load voltage detection method of circuit,
It is characterised in that it includes：
The voltage at divider resistance partial pressure end is gathered using divider resistance；
When switching tube is closed, during diode current flow, sampling keeps the voltage at divider resistance partial pressure end, and the voltage is subtracted into benchmark electricity
The partial pressure terminal voltage of divider resistance of the result of pressure with obtaining in real time is compared, instantaneous when the partial pressure terminal voltage obtained in real time
When voltage subtracts the result of reference voltage less than partial pressure terminal voltage, you can be judged as diode current zero crossing, so as to obtain two
Pole pipe ON time；
Obtain after the diode current flow time, the voltage at the partial pressure end kept using sampling, and switching tube ON time and diode
ON time, calculates and obtains load voltage.
20. load voltage detection method as claimed in claim 19, it is characterised in that in switching tube ON time, before sampling
Sampled during a cycle diode current flow the partial pressure terminal voltage of holding, in the diode current flow time, 0V voltages of sampling, by two
Sampled voltage in period is averaged, and its average value is exactly load voltage.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710534478.6A CN107271756B (en) | 2014-12-04 | 2014-12-04 | Load voltage detection circuit and method |
| CN201410729856.2A CN104360143B (en) | 2014-12-04 | 2014-12-04 | Current zero-crossing point detects circuit and method, load voltage detection circuit and method |
| PCT/CN2015/096469 WO2016086897A1 (en) | 2014-12-04 | 2015-12-04 | Current zero-crossing detection circuit and method, and load voltage detection circuit and method |
| US15/612,998 US10411685B2 (en) | 2014-12-04 | 2015-12-04 | Circuit and method for detecting current zero-crossing point, and circuit and method for detecting load voltage |
| US16/527,010 US10715125B2 (en) | 2014-12-04 | 2019-07-30 | Circuit and method for detecting current zero-crossing point and circuit and method for detecting load voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410729856.2A CN104360143B (en) | 2014-12-04 | 2014-12-04 | Current zero-crossing point detects circuit and method, load voltage detection circuit and method |
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| CN201710534478.6A Division CN107271756B (en) | 2014-12-04 | 2014-12-04 | Load voltage detection circuit and method |
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| CN104360143A CN104360143A (en) | 2015-02-18 |
| CN104360143B true CN104360143B (en) | 2017-08-08 |
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| CN201710534478.6A Active CN107271756B (en) | 2014-12-04 | 2014-12-04 | Load voltage detection circuit and method |
| CN201410729856.2A Active CN104360143B (en) | 2014-12-04 | 2014-12-04 | Current zero-crossing point detects circuit and method, load voltage detection circuit and method |
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| US (1) | US10411685B2 (en) |
| CN (2) | CN107271756B (en) |
| WO (1) | WO2016086897A1 (en) |
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| CN107271756B (en) * | 2014-12-04 | 2019-12-17 | 杰华特微电子（杭州）有限公司 | Load voltage detection circuit and method |
| EP3560085A1 (en) * | 2016-12-23 | 2019-10-30 | U-blox AG | Improvements in single inductor multiple output regulators |
| WO2019038175A1 (en) * | 2017-08-24 | 2019-02-28 | Signify Holding B.V. | A retrofit led lighting device having improved timing event detection for increasing stable driver operation without light flicker |
| CN108761329B (en) * | 2018-08-25 | 2023-11-03 | 东莞市迅迪电子有限公司 | Single-live wire switch load detection circuit and method |
| CN110554303A (en) * | 2019-09-27 | 2019-12-10 | 芯好半导体(成都)有限公司 | Demagnetization time detection circuit and method and power supply device |
| CN111044772B (en) * | 2019-12-31 | 2022-05-20 | 广州金升阳科技有限公司 | Current sampling circuit and control method |
| CN113030557B (en) * | 2021-03-11 | 2023-06-27 | 北京动力源科技股份有限公司 | Current detection circuit and current detection method |
| CN113495188A (en) * | 2021-06-22 | 2021-10-12 | 瀚昕微电子(无锡)有限公司 | Voltage fluctuation detection circuit |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN104360143A (en) | 2015-02-18 |
| CN107271756B (en) | 2019-12-17 |
| WO2016086897A1 (en) | 2016-06-09 |
| US10411685B2 (en) | 2019-09-10 |
| US20170310313A1 (en) | 2017-10-26 |
| CN107271756A (en) | 2017-10-20 |
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Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 424, building 1, 1500 Wenyi West Road, Cangqian street, Yuhang District, Hangzhou City, Zhejiang Province Patentee before: JOULWATT TECHNOLOGY (HANGZHOU) Co.,Ltd. |